809825 has 12 divisors (see below), whose sum is σ = 1039740. Its totient is φ = 624960.

The previous prime is 809821. The next prime is 809827. The reversal of 809825 is 528908.

809825 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 132496 + 677329 = 364^2 + 823^2 .

It is not a de Polignac number, because 809825 - 2² = 809821 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 809791 and 809800.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 809825.

It is not an unprimeable number, because it can be changed into a prime (809821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 167 + ... + 1283.

It is an arithmetic number, because the mean of its divisors is an integer number (86645).

2⁸⁰⁹⁸²⁵ is an apocalyptic number.

It is an amenable number.

809825 is a deficient number, since it is larger than the sum of its proper divisors (229915).

809825 is a wasteful number, since it uses less digits than its factorization.

809825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1156 (or 1151 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 809825 is about 899.9027725260. The cubic root of 809825 is about 93.2102615385.

The spelling of 809825 in words is "eight hundred nine thousand, eight hundred twenty-five".